Image quality in CT scans of the heart may be affected by heart motion. Motion of the heart within the duration of a cardiac CT scan capture may result in the presence of motion artifacts in images derived from the cardiac CT scan.
Some methods for motion compensation in CT are known in which motion (for example, cardiac motion) is estimated based on three reconstruction volumes at close time points within a single rotation of a scanner. For example, in a scanner having a rotation time of 275 ms, three reconstruction volumes may be obtained at around 70 ms apart and motion may be estimated based on those reconstruction volumes. It is known to perform motion compensated reconstruction, in which a new reconstruction volume with reduced artifacts is obtained using the estimated motion.
In some circumstances, such motion compensation methods may be tightly integrated into a CT scanner system or other scanner apparatus and may use information obtained directly from the scanner itself but that is not available from standard DICOM tags. Such information may be not available from, or stored with, reconstructed imaging data. Therefore, it can sometimes be difficult to apply motion compensation methods to stored imaging data or data processed remotely from the scanner system itself, or data processed at a later time after completion of the scan measurements.